Wafer Center Detection with DF-G2

Challenge

Detecting a wafer’s position is vital in the semiconductor industry as the wafers are valued up to $100,000 and the machines involved costs millions of dollars. Ensuring correct wafer placement prevents damage to the high-priced wafers and equipment. By detecting the wafer’s center, operators can ensure the wafer is correctly positioned on the robotic arm as the wafer is placed into the chamber.

Solution

By pairing Banner’s DF-G2 with four opposed mode PLIS-1 fiber optics, operators can ensure the wafer is on the robotic arm’s end effecter correctly so that no damage is done when passing it into the chamber. As the robotic arm moves the wafer into the chamber, the fiber optic beams will break and an algorithm will calculate the exact wafer position based on when the fiber sensing beams are broken.

Banner’s DF-G2 has a fast response time and can quickly measure and detect the wafer’s center. If the wafer is off center, the robotic arm has time to adjust the wafer to the correct position, preventing damage to the wafer and equipment.

Opposed mode PLIS-1 fiber optics have a 90⁰ viewing angle and their beam pattern is very tight, allowing for a precise measurement of wafer positioning. These fibers are also suited for high temperature environments, such as the vacuum chamber area of semiconductor manufacturing. With a limited-space area, a remotely placed amplifier with fiber optics provides an optimal solution.